Security barrier



FIG. 1 is a perspective view of the security barrier showing my new design;

FIG. 2 is a front view thereof:

FIG. 3 is a top view thereof;

FIG. 4 is a left end view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a bottom view thereof;

FIG. 7 is a right end view thereof;

FIG. 8 is an enlarged view of a portion of the security barrier shown in FIG. 8; and,

FIG. 9 is a front view of the security barrier shown in FIG. 8 in the direction shown by arrow 9 in FIG. 8. 

CLAIM The ornamental design for a security barrier, as shown and described. 